Someone effectively did that for me when I was playing my silly tree of life control druid vs his customised grinder mage in casual. We had had an epic match up until this point and just to see if I could live long enough for ysera to work a miracle for me I played tree of life. From a shredder, I had gotten Lorewalker Cho so I gave him a copy of tree of life. I think the game ground on for two more turns and then, and I don't know why, he played tree of life instead of going for lethal. I think perhaps he was just really enjoying the game and wanted to see where it would go. Through some miracle, my ysera had survived this process (the tree of lifes sure helped) and she basically single handedly managed to clear through a fairly full board including Sneeds, thanks to Ysera awakens, then kill the sneeds who spawned a deathwing and then the Ragnaros my opponent played the turn after. My opponent played very well and certainly deserved the win but he essentially gave it to me with the tree of life (although I wasn't sure to win even after it). Maybe I should have conceded at the end.
Anyway, that was one of the most fun games I have had with hearthstone and the back and forth was definitely more important than the outcome, so its not all about winning.
wow something similar just happened to me today (actually yesterday 'cause in my time zone it's already past 00:00)
I was just practicing a little with my demonlock on casual, and was with a big streak, but then, I see this druid, with a deck that i've never seen before, and now that you said it I recognize as a control druid, with ysera and stuff, While I was playing I responded to all the threats he would put against me, like I usually do, because all of them were bombs, and since I haven't used any of my own yet I would just assume he would eventually run out of threats. Damn I was terribly wrong. It seemed like everything he casted on me were bombs, i even had him set for lethal on the next turn several times, but a little taunt here and there and tree of life frustrated my dreams. And then, when I finally think he's done with bombs, and I'm free to just drop down my Mal'gannis or Jaraxxus then he comes with Ysera followed by a streak of legendaryes, I manage do clear his board once more and reach face after losing all my legendaries to his ysera dream stuff, then a tree of life comes, my deck is over, and he starts to put more legendaries on the board. And there I am, with only my hands, my opp with 30 life AND board presence AND cards in his deck. Then he just concedes. And i'm like "Holy Shit what just happened here? 0.0"
After that I just said "thank you" but thinking that I dind't deseve to win that one, I still wanted to have noted his name though :(
PS: I even had to cast Doomguard from my hand to finish a trade. WITH CARDS ON MY HAND. That's just the worst crime you can make with this deck